Transmission



May 4, 1943.

H. -R'GREEIulJEl-z ETAL 2,318,481

` TRANSMISSION Filed Dec. 14, 1940 2 Sheets-Sheet 2 wwf/ ATTORNEY Patented May 4, 1943 UNITED STATES PATENT OFFICE- 2,318,481 TRANSMISSION Harry R. Greenlee, South Bend, Loren D. Britton, Mishawaka, and John R. Bond, South Bend, Ind., assignors to The Studebaker Corporation, South Bend, Ind., a corporation of Delaware Application December 14, 194i), Serial No. 370,114

11 Claims. (Chim-#290) l -i'inderdrive or direct drive. This provides a much This invention relates to transmissions and more particularly is directed to' a transmission adaptable for use on automotive vehicles for transmitting torque from the power plant of the vehicle to the driving axle.

The conventional type of transmissionnow in use in most vehicles comprises a gear transmission having three or more speed ratios provided by trains of gears within a transmission and selected for shifting into various speed ratios under the control of the operator.

Attempts have been made heretofore to provide vehicle transmissions in which the `speed ratios are automatically selected in accordance with the load and speed conditions of the vehicle. It is with this latter class of transmission that the present invention is concerned and primarily the present invention is directed to a transmission employing a uid coupling or clutch to provide for smooth connection of the engine power to the transmission and incorporating therewith a two speed transmission using a planetary underdrive interposed between the clutch and the two speed transmission and capable of functioning in conjunction with the transmission to provide four selective driving ratios.

This produces a transmission which roughly corresponds with the present three speed'transmission plus an overdrive, it being contemplated in the present invention that the fourth speed. which is a direct connection between the engine and the propeller shaft. will be comparable to an overdrive in that the gear reduction in the driving axle is reduced so that in effect the same result is attained with a direct drive as has formerly been attained with an overdrive.

-It is therefore a primary object of the present invention to provide a four speed transmission by utilizing a relatively small simplified two Vspeed transmission and a planetary underdrive selectively operated in either of the selected speed ratios of the two speed transmission; thus the four speeds are effected as follows; first, or low, drive through the underdrive and the low speed of the two speed transmission; second. a direct drive through the planetary while maintaining the low `speed ratio in the transmission: third. underdrive through the planetary with direct drive in the two speed transmission: and fourth.. direct drive through both the planetary and the two speed transmission. This reduces to a minimum the shifting operations necessary and. in addition, allows the use of a cone type clutch for optionally shifting the planetary drive into either 1' simpler and easier shift than if a positive shift by conventional type clutch teeth, or even through synchronizer, is required.

It is highly desirable, in transmissions of this type, that over-running of the propeller shaft with respect to the engine shaft be provided during the shifting operation so that there, is no braking effect produced by the engine during the shifting operation. 'I'he elimination of the braking effect -provides a much smoother shift as well as preventing any rapid deceleration of the -vehicle during the time that the accelerator pedal is raised as the shift is taking place. The present invention accomplishes this by providing such an overruning connection. In addition, it provides a construction in which after the low speed gear in the two speed transmission has been shifted into position it need not be removed from its engaged position to shift into high speed or direct drive. The overrunning effect is automatically produced whenever the propeller shaft tends to overrun the main drive shaft and provides a very smooth shift without interfering with the accelerating characteristic of the vehicle.

Another advantage, however, in connection with the overruning feature, is the provision of means automatically operable during the shifting operation whereby the motor may be employed as a brake through the transmission, vif desired. This may be of advantage in going down long inclines when the braking effect of the motor can'j--be utilized to retard the acceleration of the vehicle, and the present construction embodies such a' selective braking mechanism.

In conjunction with a transmission of the present type in which automatic selecting and shifting of the gears by means of a hydraulic or pneumatic shift control arrangement is proposed, it is desirable that a fluidtype of coupling or clutch be interposed between the engine and the transmission which coupling is capable of absorbing by slippage the stresses due to abrupt variations in speed ratios produced by the shifting of the gears. Thus, the fluid clutch functions in conjunction with the automatic shifting features of the present transmission providing a very smooth automatically operating transmission. This clutch also allows the shifting of the gearing by the use of cone clutches, synchronizers or the like without the application of y a clutch pedal such as is reduirediin connection with the ordinary type of friction disc clutch.

Another very decided advantage produced by the present invention is the provision of an arrangement in the planetary gearing whereby the ring gear of the planetary system can be selectively coupled to the sun gear for locking the planetary in direct drive or the sun gear can be locked to the case when it is desired to provide the underdrive to the planetary. This clutching action is so designed that an overlapping effect can -be produced wherein the clutch mechanism functions to couple the ring gear and sun gear simultaneously to the'case and then selectively releasing one or the other of the clutching faces whereby a positive clutch action is produced, eliminating any slippage or tendency for chattering or walk-away in this clutching arrangement. This, in turn, eliminates the use of a positive pressure type clutch or the use of clutch springs mission which is of the same design as theV counter shaft gear for producing reverse drive.

.This gear, in conjunction with a novel type of clutching mechanism, provides a positive reverse drive through the transmission while yet allowing overrunning in any of vthe forward speeds. In this connection we prefer to employ a coil spring clutch of the L. G. S. type which can be energized in one direction to produce a clutchf ing action by expansion of the coil springs or can be energized in the opposite direction to produce a clutching action by compression of. the coil spring. If desired, however, a conventional form of overrunning clutch may be substituted but in such case additional mechanism must be employed to provide for the positive reverse and -also provide for the braking action of the motor. The two speed transmission itself is of disltinctly novel design and is capable of employment either with or without the planetary underdrlve and/or the fluid coupling. The tranmission is arranged with a synchronizer and toothed clutch for producing the direct drive between the drive shaft and transmission tail shaft and is provided with a splined gear on the countershaft for producing low speed drive through the transmission. This sliding gear action is so arranged as to remain in meshed position when the direct driving engagement is effected and consequently simplies the shifting action and readily accommodates it to an automatic control system. In addition, the synchronizer sleeve is arranged to provide means whereby when reversely shifted it will produce a positive reverse drive or may be utilized to produce a braking action of the motor on ,the tail shaft of the transmission to retard the tail shaft.

In a modified form of the two speed transmission we employ only iive gears which will produce forward drive in either one of the two speed ratios and will also produce a reverse drive.

It is contemplated within the purview of the present invention to provide a speed responsive drive. It is to be understood that the present transmission is adapted for simplied control mechanism which may be either of the positive pressure or vacuum actuated type, although we prefer the former type in which a positive pressure is employed 'for effecting the various speeds.

Other objects and advantages of the present invention illustrating the simplification of the design, ease of assembly, and adaptation of control mechanism thereto will be more apparent from the following detailed description which, taken in conjunction with the accompanying drawings, will disclose to those skilled in the art the particular construction and operation of a preferred form of the present invention.

In the drawings:

Figure 1 is a sectional view through the forward portion of the transmission showing the iiuid clutch and planetary gearing;

Figure 2 is a sectional view taken substantially on line 2-2 of Figure 5 showing the details of the two speed transmission which is driven from the planetary gearing;

Figure 3 is a detail sectional view of a portion of Figure 2 modified to incorporate therein an overrunning clutch;

Figure 4 is a detail sectional view of a further modification of Figure 2 in which one of the gears has been eliminated;

Figure 5 is an end elevational view, partly in section, showing the relative arrangement of the main shaft, countershaft and reverse idler shaft of the transmission;

Figure 6 is a top plan view, partly in section, showing the clutching arrangement for actuating the coil spring clutch;

Figure 7 is a detail sectional view of the neu'- tralizing means for the planetary clutch control means; and

Figure 8 is a detail sectional view of another means for actuating the planetary clutch.

Referring now in detail to the drawings, in Figure 1 there is illustrated a housing portion A adapted to be pilottd in and bolted to the rear face 5 of the engine block, and which forms a closure for the uid coupling indicated generally at B. The fluid coupling is adapted to drive the planetary gearing indicated generally at C and a two speed transmission generally indicated at D in Figure 2. From this transmission suitable 4 connection is made through a propeller shaft,

torque tube, or the like, to the rear driving axle of the vehicle.

The opposite side of the housing 6 formed by' the cup-shaped member I0 is provided with a radially inturned ange I2 which by means of the studs I3 is secured to a seal supporting member I4 having splined or toothed engagement as indicated at l5 with a sleeve member I6 rotatable on the driving shaft I1. Maintained within the casing 6-I0 of the fluid coupling is the rotor member I8, which is provided with a plurality of fins i9 corresponding to the iins 20 of the imasrsicsi peixer s. AThe memberla is belted. or riveted, as

at 2|, to a sleeve member 22 vmounted upon the A reduced splined end 23 of the shaft |1. A suitable bearing 24 centers the sleeve `22 Within the endof the crank shaft 8 and the opposite end of the sleeve rests upon the shaft l1. It will thus be apparent that whenever the housing 6 is rotated-with the ns 28 and |9 filled with oil or a similar fiuid. the rotor i8 will tendto rotate therewith thus effecting rotation of the shaft l1. Secured to the rear end flange 25 of the housing A. is a substantially annular housing 26 which is bolted -to the flange 25 by means of the studs 21, there being an intermediate partition member 28 interposed therebetween. The member 28 has a cylindrical extension 29 provided with a bearing seat for-the bearing 38 which centers the opposite end of the shaft I'L The member 28 has its opposite face provided with an axially extending eccentric recess adapted to be closed 'by the plate 32 and which receives the meshing gears 33 and 34 of an oil pump. The .pump gear dra-ws oil through the conduit 35 from the sump 36 in the bottom of the casing 26 into tl'ie pump and then discharges the same under pressure into the fluid impeller in any suitable manner.,

By reason of the splined connection I between spaced set of teeth 62 adapted to have meshing engagement with the member 93.1 The member 99 is riveted or otherwise secured to the member 58 and has ahub portion 64 rotatably supported by means of a suitable bushing upon the shaft 59. The hub portion 84 of the member l93 has mounted thereon a ball bearing assembly 95 which, in turn,` rotatably supports a radially extending member 68 having its -outer yperiphery secured in the annular piston 81. Since the clutch portion-58 of the member 83 is. rigidly secured thereto, itis apparent that axial movement oi' the member 63 will result in moving the friction surface 49 of the member 58 into and out of engagement with the friction ring 48. This `produces coupling engagement between the sun gear 59 and the ring gear 45, thereby locking the twov together for conjoint rotation to produce a direct drive from theshaft I1 to the shaft 66 through the planet spider.

The member 58 is also provided with an external conical brake surface 68 adapted to enthe housing I8. and the sleeve I6, the gear 33 being keyed to the sleeve .as indicated at 38, it is apparent that whenever the crank shaft 8'is rotated 4the gear 33 will be correspondingly rotated and consequently will actuate the pump to provide the desired oil pressure. The gear 34 is journalled upon a stub shaft 39 mounted at its ends in the member 28 and the cap 32.

A suitable bellows type seal V48 is interposed between the sealing member I4 and the external gage. the corresponding surface 69 of an annular ring member 18 mounted for axial sliding movement within the cage 26 by means of a plurality of circumferentially spaced members 12 extending into the cylinder 13. Suitable internal splines in the cage 26, as indicated at 14, prevent the member 18 from any relative rotation. It will be apparent that when the clutch and brake member 58 is shifted to the right, as shown in Figure 1,` to produce a braking engagement between the member 18 and the clutch and brake or torque transmitting member 58, the sun gear 59 will be Alocked against rotation and consequently underdnve will be effected from the shaft l1 tc the shaft 58 through the'planetary gearing. Prefery ably suitable springs (not shown), normally urge surface of the impeller 6 to prevent loss of fluid therepast. This seal member may be of any desired type although we have found that the best results are attained with a bellows seal such as shown at 48 and a friction surface seal provided by the ring washer 42 and. engaged by the coil,

spring 43. This effectively seals the oil against passage outwardly into the housing A. If desired, the baffles 4| on the casing I8' can be employed for securing circulation of air about the fluid clutch to maintain the same at the desired operating temperature.

. 46 has the external friction surface adapted to be engaged by theclutch' surface 49 of a conical clutch and brake member indicated generally at 58. The internal ring gear teeth 52 of the member are adapted to have meshing engagement with the corresponding teeth of the planet pinions 53 carried by means of the shafts 54 upon a planet spider 55 which spider has Aan extended hub. portion 56 having splined engagement with the splined end 51 of a main drive shaft 58.

Rotatably mounted upon the sleeve or hub portion 56 of the spider 55 is asun gear member 59 which has teeth 58 meshing with the planet Insuch case air would Abe introduced at the radial inner ends of the the member 18 to the right, as viewed in Figure 1, being Abiased, between plate 28 and the left-hand end face of the. member 18.

- The rear end of the cage 26 is provided with an end portion 15 which includes an axially extending bore 16. Closing the end of the bore is a bracket member 1| which receives one end of the ball bearing assembly 11 carried by the flanged end 18 of the housing D which encloses the two speed transmission. At its outer end the shaft 58 is radially enlarged as' indicated at 88 to provide a drive gear portion 82 and is axially recessed-to receive the pilot end 83 of the main transmission shaft 84 which isjournalled therein by means of the roller bearings 85. Mounted within the end plate 1| of the bore 16 of the vhousing 26 is a seal member 86 which seals one end of the bearing 11. 'I'he plate 1| is secured to the end of the housing D by means of studs 81.

This member also has secured therein suitable axially extending circumferentially spaced studs 88 which extend through suitable apertures formed in 'the an-ge portion of the member 68 to prevent relative rotation of this member so that the periphery of the member B6 may be retained in suitable recesses 89 formed 4in the annular piston 61. The piston 61is provided about its external periphery with a substantially V- shaped groove 98 and the opposite ends of the piston are axially recessed as indicated at 92 and pinions 53 and which is provided with an axially 75 93. The member 1| forms with the bore 16 of the housing 26 and the flange member 94 a suitable annular recess forming a cylinder for reception of the piston 61. The member 94 is secured by means of studs 95 to an offset portion of the bore 16 and forms one end of the cylinder assembly.

Mounted at circumferentially spaced points intermediate the cylinders 13 whichcontrol the operation ofthe pistons 12 are a plurality of neuy tralizing devices shown more clearly in Figure 7. These are for the purpose of centering the piston 81relative to the cylinder in such manner. that the friction surfaces 68 and 49 are spacedaway from the corresponding friction surfaces 69 and 46so tliat the-member 50 remains in neutral position.

This neutralizing' mechanism ing member 96 mounted in any suitable manner on the periphery of the right-hand end of the housing'26 'and suitably bored toyform the chamber 91. Atthe base of this chamber there is formed an :opening 98 which is disposed substantially adjacent the annular groove 90 inthe piston 61; (A suitable spring retainer 99 forms a seat for one end. of a spring extending vertically in this chamber and biased at its 'opposite end against thev end assembly |02 of a neutralizing plunger |03. 'I'he plunger |03 has thereon the cup shaped cap |04 which at one ,side is provided with a laterally extending ear |05 adapted to 'slide within the groove |06 for preventing rotation of the assembly. The plunger |03 hasa tapered lower end |01 adapted to engage in the groove 90 for centering the piston 61 within the annular cylinder. The neutralizing member is operated l includes a housers at opposite ends'of the-sleeve retain yit in position. Also splined upon the sleeve |26 is an operating gear member |32 having at one end thereof the annular groove or yoke collar |33 for receiving the shifting fork and having at its opposite end the reverse speed idler gear or low speed gear |34 of the transmission. The member |32 is adapted forsliding movement axially on the splinesf |35 of the sleeve |26 and when shifted axially to the right from the position shown in Figure 2 is adapted to have meshing engagement with the teeth |36 of a gear member |31 which is suitably mounted by means of studs |38 upon the radial iiange |33 of a hub member |40 suitably supported by means of bushings 4upon the shaft 84. Between the gear |31 and the gear 82, the shaft 84 is splined as indicated at with the clutch teeth |45 of the gear 82 whereby iluid pressure the spring |00 urges the plunger upwardly to condition the piston for operation.

The housing member 96 is adapted for eccentric' mounting on the housing 26 to provide for adjusting the neutral position of the piston 61. The details of the functioning of the mechanism will be discussed hereinafter.

Considering now the plurality of cylinders 13 spaced circumferentially about the rounded end of the housing 26, these cylinders are adapted tot receive the piston heads ||2 of the pistons 12 which actuate the ring member 10. The end of `the cylinder is closed by a suitable plug 3. Suitable ports ||4 and I5 in the cylinder operate to admit fluid pressure to opposite sides of the piston head |2 for shifting the member 10 axially in opposite directions. The details of this construction and its functions will be described later.

Considering now the structure shown in Figure 2 of the drawings which is' the two speed transmission mechanism, the housing 18 of this mechanism is closed at its rear end by a transverse member |20 which member has an oifset bearing'portlon |22 Vadapted to receive the ball on a countershaft |28 journaled at one end in the end l18 .of .the housing and at the other end in' a transverse web |29. Suitable thrust washthe member |51 and the ring |62 and thence the sleeve |44 clutches between the gear 82 and the hub portion |43 to directly couple the shafts 58 and 84 for driving engagement.

The enlarged end of the shaft 58 is also provided with a friction surface |46 adapted to be engaged by the friction cone |41 carried by the synchronizing portion |48 of the clutch |44. The ring or cone is normally urged into frictional engagement with the surface |46 by means of axially directed springs. |48 carried within the hub member and bearing against the inner lflanged end of the member |48. 'I'his particular synchronizing structure' is similar to that described in the copending application of 0. K. Butzbach, Serial No. 343,938, filed July 5, 1940.' The toothed portion |50 of the hub member |43 has formed therein at circumferentially spaced points the poppet balls |52 which are adapted to engage in suitable recesses |53 formed lin the internal splines of the sleeve |44 to act as detents therefor whereby initial shifting movement of the member |44 will carry the hub |43 axially to the left to bring the friction surfaces |46 'and |41 into positive engagement for synchronizing the speeds of the shafts 84 and 5B prior to moving the clutch sleeve |44 into clutching engagement.

Suitably mounted upon the splines |55 of the shaft 84 is the hub portion |56 of a gear member |51 which has external gear teeth |58 formed adjacent the gear teeth |36 and spaced therefrom by means of the thrust washer |59. 'I'he external axially directed portfn of the member |51 has bearing engagement on the cylindrical portion |31 of the gear |36 by means of a bushing |60. Mounted Within the annular space between the end of the cylindrical portion |31 of the gear |36 and the end flange of the member |51 is an annular ring |62 which is secured to the member |51 by m'eans of the 'rivets |63. This member forms an internal cylindrical bearing surfaceito be acted upon by the coils of thc helical spring clutch |64. This clutch` I ,64 is anchored at one end as indicated at |65 in Fg-' ures 2 and 6 in the. end portion of the member |51 and extends axially between the hub |56 and into the annular space between thesleeve |40 of the member |39 and the inner surface or annular portion of the gear member |31. At its inner end the coil spring member is provided with a normally directed lip |66 which is adapted to be engaged by the radially inturned end of a 'of the snap ring |68.

Mounted upon suitable dowels and studs |12 carried by the flanged portion |39 of the member |40 is a radial plate member |13 which is normally spring-pressed toward the synchronizer sleeve |44 by means of springs |14. The inner end of the studs |12 have secured thereto the annular sleeve member which at its inner end is provided with the recessed or notched portion |16 shown in Figure 6. When the synchronizer sleeve |44 is shifted to the right, as viewed in Figure 2, it abuts against the plate |13 thereby urging the sleeve |15 axially to the right to move the notched portion |16 thereof into engagement with the end |66 of the spring |64. Under such conditions, if the tail shaft 84 is rotating at a faster speed than the engine with the first speed gear |34 in meshing engagement with the gear |36 there will be a difference in relative rotation of the member |51 and-the gear member |31 which, in turn, results in a difference in rotation between the member |51 and the member |40 secured to the gear member and carrying the sleeve 15. This results in `contraction of the spring coils thereby locking the spring |64 to the external annular surface of the member |40 and providing positive clutching engagement between the member |51 and the member |40 to produce a braking action when, and if, desired so that the engine acts as a brake upon the tail shaft.

With the plate member |13 in the position shown in Figure 2 there is no tendency to contract the coils of the spring |64 and, consequently, these springs will remain in a normal intermediate position in which the member |31 will not be clutched with the member |51. ever, when the rst speed gear |34 is moved into meshing engagement with the gear teeth |36 and is driven by the shaft 58 it will tend to rotate the gear |36 at a speed greater than the speed of the member |51 since this is the low speed drive through the transmission. As a result the teaser spring |18 will act through the member |61 to energize the coils of the spring |64 in the opposite direction expanding the same to produce a clutching action between the internal annular surface of the gear member |31 and the internal annular surface of the ring |62 secured to the member |51.` As a result, as long as tho How- of links |93 to pivots |94 vcarried on a yokev member |31 tends to overdrive the member |51 j there will be a positive clutching action caused by expansion of the spring coils and a positive drive to the shaft through the splines will be produced.

However, the shaft 84 tends to overrun with respect to the driving gears |34 and |36, during release of the accelerator prior to shifting. lThe spring |64 -then returns to a neutral position allowing the shaft 84 to overrun relative to the gear |36 so that there is no momentary braking action of the engine during this interval. This overrunning action will be effected as long as the first speed gear is in engaged position with the gear |36 regardless of whether the direct or underdrive is provided through the planetary.

The housing |24 has secured to the rear end thereof the conical housing |80 having a flange |82 secured through the intermediate member |20 to the end of the housing |24 by means of studs |83. The tail shaft 84 extends through the housing |80 and is suitably supported adjacent its rear end by means of the bearing assplines |55 of the tail shaft 84. r

sembly |84 adjacent the rear end |85 of the 75 housing |80. The projecting end of thc shaft 84 indicated at |86 is splined to receive the companion flange of a universal joint assembly which connects the tail shaft to the propeller shaft. Disposed Within the housing the shaft 84 is provided with a speedometer gear |81 of conventional design and is also provided with a governor mechanism comprising a fixed portion |88 keyed to the shaft 84 andcarrying the opposite pivots |89 which through the links |90 'are connected to the toggle joints |92 acting as the centrifugally movable members of a governor mechanism connected through the opposite pair collar |95. Il. will be apparent that as the speed or rotation of the shaft 84 increases the toggle joints |92 move radially outwardly under the influence of centrifugal force, thereby tending to move the yoke |95 axially to the left along the shaft 84. This results in compression of the double coil springs |96 and |91 which resist this movement and which can be adjusted to control the point at which the yoke collar |95 will move suciently to actuate suitable valving mechanism for controlling the shifting within the transmission.

Referring again to the two speed transmission of Figure 2, an idler shaft 200, shown in Figure 5. is provided within the transmission housing and carries thereon an externally splined sleeve |99 slidably receiving the gear 202 which has a yoke portion 20| for receiving a shift fork. vThe gear 202 is an idler gear carried on the shaft 200 and when moved to the left from the position shown in Figure 2, is adapted to have meshing engagement with the gear teeth |58. The opposite end of the shaft sleeve |99 has a fixed gear 203 adapted to be driven by the gear |34 when in the position shown in Figure 2, whereby the gear |58 is driven in a reverse direction when the gear 202 is shifted to the left from the position shown in Figure 2 into meshing engagement with gear |58. This results in providing reverse drive through the transmission to to the tail shaft as indicated at |55. This reverse drive is independent of the spring clutch and provides a positive reverse from the gear |34 to the gear 203 and thence through the gear 202- to the gear |58. Thus there is no overrunning or free wheeling in reverse drive.

In the form of the invention shown in Figure 3 the spring clutch is eliminated and a more or less conventional type of overrunning clutch indicated at 205 is inserted between the gear |36' and the gear |58'. The gear |58' in this form' of the invention is provided with a radially anged end portion 206 which is rigidly secured as at 201 to a hub member 208 mounted on the The member 208 also has a clutch journal surface 209 forming the inner race for the overrunning clutch 205. The overrunning clutch 205 is mounted in a. retainer 2|0 carried within and preferably cast integrally with a bearing support 2|2 which at one end forms a thrust :flange 2|3 between the :flanged portions of the hub member 208 and the cylindrical extension 2 |4 of the gear member 2|5 carrying the rgear teeth |36'. The retaining member 2|2 is locked by means of splines or the like for limited rotation relative to the hub member 208 and a suitable coil spring 2|6 normally urges the clutch assembly into inoperative position.

The gear member 2|5 is provided with a. clutch toothed portion 2|| adapted to be engaged by 'tated. This is of distinct advantage.

' right as viewed in Figure 3 to provide a positive clutch between the'shaft 84 and the gear member 2|5. Thus a positive low speed drive can be provided if desired. However, in normal operation the gear |34 on the counters'naft will drive the gear |36' which through the overrunning clutch 205 will pick up and drive the hub member 208 for driving the tail shaft.

. gaged in the corresponding collars 20| and |33 Whenever the tail shaft begins to rotate faster than the gear |36' the clutch will function to 'release engagement therebetween and allow a free wheeling action. The reverse gearing is operated in this form of the invention in the same manner as described in connection with Figure 2.

l The positive clutch between the gear |36' and the shaft 84 is for the purpose of being able to crank the motor by moving the vehicle and provides a construction corresponding to that shown in the copending Greenlee application, Serial No. 358,393, filed September 26,A 1940.

In the construction shown in Figure 4 the mechanism is substantially the same as shown in Figure 2 with the exception that the gear teeth |58 have been removed from the member |51. This then requires that the reverse slider 202 be of the respective gears. Preferably the transverse web or partition 228 formed in the transmission housing for supporting the lay shaft 200 is provided with a suitable pin member 229 extending longitudinally of the transmission and providing a support for the notched portion 230 of the shifter fork 224 to maintain it in position without imposing any radial stress upon the yoke portion 20| of the gear 202.4 The particular mechanism by which the forks 224 and 225 are shifted forms no part of the present invention but suffice it to say that the actuating means is hydraulically controlled by means of suitable valves and pistons which are operated in accordance with the governor mechanism shown in Figure 2, so far as shifting the clutch sleeve |44 is concerned. So far as the reverse idler gear is concerned, the shifting of this gear can be manually controlled by a simple lever which moves the gear into meshing engagement with either the gear |36 or the gear |58 and when in its Opposite position shifts the gear 202 into neutral position.

Considering now in detail the mechanism shown in Figure 8, this is a revised arrangement of the piston construction for the piston ||2 and the ring 10\of Figure 1 and provides a more desirable design insofar as actuation of the gear is concerned.

moved to the left so that it can be moved into clutching engagement with the gear |36 instead of within the gear |58. The spring clutch ,ar-

rangement functions in exactly the same manner' as previously described, allowing the gear |36 to couple to the shaft through the member |51 by expansion of the clutch coils and to be uncoupled from the member `|51 when this member tends to overrun the gear |361. The advantage of such a construction is the elimination 'of the gear teeth |58 thereby reducing materially the cost of the construction and the shortening of the shaft portions on which the reverse gears 202 and 203l are mounted. It will be apparent that whenever the gear |34 is shifted into meshing engagement with the gear |36 in any of the forms of the invention shown in Figures 2 to 4, thelay shaft 200 will be uncoupled from any gearing engagement and, consequently, will not be ro- One of the distinctions between the construction shown in Figure 2 and that shown in'Fgure 4 is the fact that the reverse drive in the latter form of the invention is coupled to the tail shaft B4 through the spring clutch |64, this clutch being revers'ely energized under such conditions to provide the coupling engagement.

The shifting mechanism ior the gears |34 and 202 is shown somewhat diagrammatically in Figure 5. It will be seen that the transmission housing cated at 220. Disposed in vertically spaced arrangement within this opening are the shift rails 222 and 223 mounted in suitable journals formed in the transmission housing. Each of the shift rails is provided with a shifter fork indicated at 224 and 225 having projecting notched lug portions 226 and 221, respectively, adapted to be engaged by any suitable actuating means for shifting the fork and rail axially to move the respective gears into the desired position. `The shifter forks 224 and 225 have yoke portions en- |24 is provided with a side opening indi- In Figure 8 this ring is formed in two pieces, the portion 235 having an axially extending piston portion- 236 slidably mounted within an annular cylinder 231. is anannulus 238 suitably formed to have locking engagement in the splines 14 of the housing 26 to prevent rotation of the piston. The housing 26 is provided with circumferentially spaced boss portions 240 which are provided with longitudinally drilled passageways 242 and radial passageways 243 for admitting uid, under pressure, into the cylinder 231 to actuate the piston 236. With the clutch torque transmitting member 50 in neutral position, that is, intermediate the member 235 and the ring gear 45, the shift from this neutral position to underdrive is accomplished as follows:

The piston 61 is provided with a port 245 for admitting uid, under pressure, tothe right-hand end thereof and is also provided with a passageway 241 which, through the passageway 248 and the port 249, isadapted to admit fluid, under pressure, to the left-hand side of this piston which controls the shifting movement. of the clutch and brake member 50. Thus, in shifting .from neutral to underdrive, oil pressure is supplied through the ports 243 and 249 with the pressure lin the line 241 being greater than the pressure in the line 242. As' a result, the piston 61 tends to move to the right while the piston 236 has a tendency to move to the left'. This produces immediate engagement between the'friction surfaces 68 and 69 and due to the differential in pressure causes the piston 236 as well as the piston 61 to move to a stopped positionwith the portion 235 resting against the shoulder formed by the end of the cylinder 94 and with the piston 61 urged to its furthermost right-hand position. 'Ihis provides a minimum loss of time for producing engagement between the surfaces 68 and 59 when a shift from neutral to under- Bolted to the portion 235A 45, the pressure in the port 243 is increased to extend the pressure in the passageway 241. As a result, both the piston 236 and the piston 231 are carried to the left so that the friction surface 49 of the torque transmitting member 50 engages the cone 46. Through .this shifting movement the underdrive is maintained which is an important feature. moved to the left a suitable slot 250 in the piston 236 communicates with the outlet port 246 and a suitable time interval, due to the size of the opening and the arrangement of the pressure controlled system, is provided during which the friction surfaces 49 and 46 arelmomentarily held as a suitable hydraulic valving mechanism trips to apply pressure to the port 245, thereby forcing the member 66positively to the left in order to hold the surfaces 49 and 46 in driving engagement while the bleeding of the pressure from the cylinder 231 outwardly through the port 246 releases the pressure on the portion 235. It will be noted that at this time the friction surfaces 49 and 46 are positively engaged for direct drive while the piston 236 which is now unloaded of pressure from the port 243 du'e to the bleeding off, floats back to its extreme right-hand position under the influence of springs (not shown), thus permitting runnin-g clearance between the friction surfaces 68 and 69. The planetary, under this set of conditions, is locked for direct drive with the ring gear andsun gear allowing for conjoint rotation between the friction surfaces 49 and 46.

In order to shift back from the direct drive to underdrive, oil pressure is again applied through the passageway 242 into the right-hand end of the cylinder 231 with a greater pressure being applied through the passageway 241 into the port 249. However, this greater pressure in the port 249 is higher or equals the pressure through the port 245 and thus there is no axial movement in the piston 61 until the pressure is released at the port 245. However, during this time the portion 235 `irst travels to the left so that its slot engages with the port 246 and a bleeding oif is thus provided so that the torque transmitting member 50 is momentarily held during the interva1 in which the hydraulic valve in the control is shifted to reduce the pressure at the port 245.

The release of pressure in the port 245 causes the pressure at the left-hand side of the piston 61 to become greater than the pressure in either the port 245 or the port 243 and the entire assembly of the member 235, torque transmitting member 50 and piston 61 moves to the right into the position described above for producing an under drive with the sun gear locked against rotation by the positive engagement of the surfaces 68 and 69. This provides running clearance between the friction surfaces 69 and 46 and also insures that as soon as the pressure is introduced to the passageway 242 the parts will be locked in underdrive and will remain in underdrive during the shifting thereof to the right out of engagement between the friction surfaces 49 and 46.

Considering now the operation of the structure as disclosed in the instant application, it will be apparent that whenever the motor of the vehicle is operating, the sleeve i6 will be rotating and thereby operating the gear pump 33-.34 to force a supply cf oil into the fluid coupling B. As the engine speed increases the impeller of the coupling will start to drive the rotor I8 thereby rotating the shaft II upon which is carried the As the two pistons are ring gear member 45. So long as the member 50 remains in the neutral position shown this Will result in merely idling operating of the mech- -mism as the sun gear is free to rotate.

If it is desired to start the vehicle oif in its lowest speed ratio the gear |34 in the transmission is shifted into meshing engagement with the gear |36 and is allowed to remain in this position throughout the normal forward driving range. This shift can be controlled by a small lever on the steering column which merely is shifted in one direction to eiect a forward drive and in the opposite direction is operable to shift the gear 292 into engagement with the gear |58. The remainder of the drive can be automatic in operation. As the shaft I1 is driven from the fluid coupling, fluid pressurehis applied as described hereabove through the ports 243 and 249, or through the ports ||4 and ||5, to the lefthand side of the piston 61 in the construction shown in Figure 1, with the pressure in the lefthand side of the cylinder housing of piston 61 being greater than the pressure at ||4 or at 243. This produces the pressure differential causing the torque transmitting 50 to move to the right until it rests against the housing 26. During this movement the brake faces 68 and 69 are locked in positive driving engagement, thereby locking the sun gear against rotation to produce the underdrive through the planetary system. As a result, the ring gear 45 of the planetary drives the spider 55. carrying the planet pinions, and consequently drives the shaft 58' which' through the countershaft |35 and the gear |34 drives the gear |36 in thetrans. `ission. This gear is free to rotate relative to the iaft 84 butas it starts to overrun with respect to the gear |51 the spring |64 is energized, thereby effecting a friction clutching engagement between the gears |36 and |51 so that the drive is transmitted to the main shaft 84. A

As the speed of this shaft increases, the governor mechanism in the housing begins to function, moving the shift collar to the left. This, in turn, operates a suitable valve mechanism in a fluid controlled circuit for shifting the synchronizer sleeve |44 into engagement with the clutch teeth |45 of the gear 82, thereby producing a direct drive between the shafts 58 and 84. I'his direct drive can be effected while the gear |34 remains in meshing engagement with the gear |36 since the gear |31 is free to overrun relative to the gear |56. Thus, a direct drive through the transmission is effected which is preceded by an underdrive through the planetary system. As the speed further increases the sleeve |44 isshifted out of engagement. Simultaneous with the shifting of the sleeve |44 out of engagement, the hydraulic control system functions to shift the planetary system from a low ratio drive to direct drive. This is accomplished by shifting the member 19 to the left and at the same time holding the member 50 in positive engagement with the ring gear 45. As the member 10 moves into a position to engage the brake surfaces 68 and 69 there is a momentary time interval during the tripping of the hydraulic valve which controls the uid pressure at the right-hand side of the piston 61. As pressure is applied to the right-hand side of the piston 61, pressure is released at the left-hand side of this piston and also at the left-hand side of the piston ||2. The springs therefore move the member 10 out of driving engagement while the pressure maintains the member 59 in its left-hand position to engage the clutch surfaces 46 and 49 for positive drive. This locks the sun gear and ring gear together for conjoint rotation. The direct drive through the planetary rotates the shaft 58 ccnjointly with the shaft |1 and, in turn, drives the shaft 84 through the reduction gear in the countershaft in the same manner as previously described.V

As the torque speed increases further the governor mechanism may function to shift the synchronizer sleeve to a position effecting direct drive between the shafts 58 and 84, thereby producing direct drive from the fluid coupling through the entire transmission structure.

It is to be understood that the particular control means and the particular sequence of the drives can-be varied as desired.` For example, the drive can be an underdrive through the planetary and a reduction through the transmission,

then a shift to a direct drive through the planetary with a reduction through the transmission and a subsequent direct drive eliminating the reduction change in the transmission. Optionally, the drives could be arranged to provide an underdrive through the planetary with a reduc. tion through the transmission, then a shift to direct drive in the transmission and a final shift into direct drive through the planetary. Thus, by properly arranging the control system the present construction. is capable of a combination of different driving ratios, available for use andi:

controlled in accordance with the torque and lspeed conditions encountered.

If it is desired to effect reverse drive, the gear |34 while in neutral is in constant mesh with the gear 203 of lay shaft 200. The gear 282 is then shifted into engagement with the gear |58 whereby upon actuation of the member 50 reverse drive can be effected to the gear |51 and thence to the shaft 84 either in underdrive or direct drive through the planetary although preferably this will be arranged to operate through the underdrive of the planetary.

If it is desired to use the motor as a brake, as, for example, coming down hill, the synchronizer sleeve |44 can be shifted rearwardly to engage the plate |13 which, in turn through the sleeve energizes the spring |64 in a reverse direction thereby coupling the gear |51 to the gear |35 and consequently coupling the shaft 84 back through the reduction gearing to the engine through the fluid coupling to provide an engine brake for retarding the speed of the vehicle when coasting. This can be either manually or auto. A matically controlled.

'The forms of the invention shown in Figures 3 and 4 will provide similar operating sequences, the only difference between Figure 2 and Figure 3 being the use of an overrunning clutch 245 in place of the spring |54 and the provision of means for directly coupling the gear to the shaft 84 in place of using the plate |13 and reversing the energization of the spring |54.

In Figure 4 a construction substantially identical with Figure 2 is provided, except that the teeth |58 of the member |51 are eliminated and the reverse gear 202 is adapted to be shifted directly into engagement with the gear |35. In its Yother respects, this construction is the same in so far as the operating sequences are concerned.

Similarly, the means for operating the friction member 18 can be varied-as shown in Figure 8 in which a dierent type of piston arrangement is provided. However, the functions are yequivalent but in this form of the invention the equalizing or neutralizing member of Figure 7 and which provides all the various driving ratlos necessary to utilize the transmission undervarious conditions. For example, on straight level driving it will probably never be necessary to employ the underdrive of the planetary in conjunction With the reduction gearing, but it might be highly desirable in muddy Weather orvfor hill climbing or the like when greater speed reduction is required. l

We are aware that numerous changes may be made in certain details of construction of the present invention and in details of the various elements disclosed in the instant application and we therefore do not intend to be limited except as defined lby the scope and spirit of the appended claims.

We claim:

1. In a transmission having a iiuid couplingand connecting power source therewith, a planetary gear system including a ring gear driven by said coupling having an external conical frictionthe same direction and substantially parallel with the outer friction surface of said torque transmitting member, fluid actuated means for shifting said torque transmitting member, and uid actuating means for shifting said non-rotatable Abrake member, said last two means being actuatable to couple said sun gear to said ring gear or to said non-rotatable brake member, optionally.

2. The combination of claim 1 characterized by the provision of means for positioning said torque transmitting member so that the vfriction surfaces thereof are out of engagement with the friction surfaces of said ring gear and said nonrotatable brake.

3. In combination, a fluid coupling including a driven shaft having a ring gear at the endA non-rotatably located within said housing for axial shifting movement, a drive shaft, a planetary ring gear connected to said drive shaft and having an external friction surface in radial alinement with said friction member, a planet spider having planet pinions driven by said ring gear, a driven shaft connected to said spider, a sun gear for said system, a torque transmitting member splined on said sun gear and shiftable with said annular friction ber having inner and outer friction surfaces fc-r engaging the friction surface o f said ring gear and said annular friction member, respectively, means for selectively shifting said torque transmitting member, and means for selectively shifting said annular friction member, said last two means being actuatable to connect said ring gear and said sun gear together to effect a direct drive through said system or to prevent rotation of the sun gear to effect a ratio drive through said system, optionally, while maintaining continuous torque to the driven shaft. y

5. The combination of claim 4 characterized by .the provision of means for positioning said torque transmitting member to dispose the friction surfaces thereof out of engagement with thev friction surfaces -of said ring gear and said annular friction member.

6. In a planetary system for a transmission, a

' housing, an annular friction member non-r0- tatably located within said housing for axial shifting movement, a planetary ring gear having an external friction surface in radial alinement member. a sun gear for said system, a. torque transmitting member for said sun gear having a peripheral portion -lying between said friction member and said ring gear friction. surface, means for shifting said torque transmitting member axially to lock said -sun gear to said ring gear or to lock said sun gear to said friction member, said means comprising an annular piston, and means for selectively admitting fluid under pressure to each end of said piston and radially movable fluid actuated means for forcing said piston into neutral position.

'1. In combination, a fluid coupling. a planet gear system including a ring gear driven from said coupling, a sun gear. and a pinion spider, a shaft driven by said spider and having drive gear means thereon, a transmission main shaft journalled at one end therein, uid operated means for simultaneously locking said sun gear and ring gear against rotation and selectively releasing said ring gear for rotation or releasing said ring gear and sun gear for conjoint rotation to provide an underdrive or direct drive to said driven shaft, and uid control means operable to return said locking means to neutral position.

8. A planetary gear system adapted to be ln' terposed between a fluid coupling and a trans' selectively operable coupling, a planet spider fortransmitting drive to said transmission, a sun gear, a .rst axially shiftable torque transmitting member keyed to said sun gear, a non-rotatable axially lshiftable raking member overlying said torque member, and selectively operable control means for each of said torque transmitting and braking mem,- bers for coupling said sun gear to said ring gear, or to said braking member or to both.

9. The combination of claim 8 wherein said torque transmitting and said clutching members are shiftable selectively or conjointly in either direction under selective influence of said control means. Y

10. In a planetary gear system adapted to be interposed between a. uid coupling and' a change speed transmission, including a ring gear, a sun gear and planet spider having pinions geared therebetween, a i'lrst clutching member splined on said sun gear and axially shiftable in opposite directions from a neutral position, a housing enclosing said system, a non-rotatable axially shiftable ring member in said housing, said ring member and ring gear having radially spaced coaxial overlapping friction. surfaces, said clutching member having a corresponding co' axial clutch portion interposed inv said space and optionally engageable with each upon axial shifting, and means for selectively shifting said ring member to engage said clutch portion when in, one shifted position and to maintain said engagement as said clutch member is shifted to its other shifted position.

11. A planetary gear system adapted to beinterposed between a uid coupling and a transmission, comprising a ring gear driven by saidl coupling, a planet spider adapted to be driven by said ringygear, a sun gear, a torque transmitting member keyed to said sun gear and shiftable axially thereon, a non-rotatable axialLv shiftable brake. member overlying said torque member, control means for said torque transmitting member and said non-rotatable brake member for coupling said sun gear to said ring gear, or to said nonrotatable brake member, or to both, and meansfor maintaining said torque transmitting member in neutral position. v

of said surfaces v 

